This invention relates to a surgical stapling control means which prevents the trigger in a stapling instrument from partially forming a staple and then returning and picking up the next staple.
The Applicants are not aware of any prior art references which in their judgements as persons skilled in the art would anticipate or render obvious the control means of this invention. However, to develop the background of the invention and to establish the state of the art, the following reference is cited. U.S. Pat. No. 3,873,016, which is incorporated by reference. This reference discloses a stapling instrument including a ratchet means.
The surgical stapling control means has advantages over the prior art reference. The control means prevents the trigger from returning to its initial position if the compression is interrupted. Thus has the advantage of preventing a second staple from being formed on the anvil flange before a first staple is separated from the instrument. Another advantage of the control means is interrupted stapling. The surgeon can now stop the compession of the trigger into the handle to realign the instrument over the wound site. Thus the possibility of a perfect stapling procedure is greatly enhanced. Finally, the control means are automatically disengaged on completely compressing the trigger. Thus, the control means do not have to be manually reset after a single staple is formed and separated from the instrument.
A surgical stapling control means has now been invented. The control means are contained in a surgical instrument comprising a handle; a trigger pivotally attached and on compression internal to said handle; and staple forming means contained in the forward portion of the handle.
The control means comprise a multi-toothed ratchet on the rearward position of the trigger; at least one guide pin attached to the initial end of the ratchet; a nonpivoting pawl attached to the rearward portion of the handle to coordinate with the ratchet; and guide means adjacent the rearward portion of the handle to coordinate with and provide tension to the guide pin.
An alternative surgical stapling control means has also been invented. The control means are contained in a surgical instrument comprising a handle; a trigger pivotally attached and on compression internal to said handle; and staple forming means contained in the forward portion of said handle.
The alternative control means comprise a multi-toothed ratchet on the rearward portion of the handle; a pawl attached to the rearward portion of the trigger to coordinate with the ratchet; at least one guide pin attached to the initial end of the pawl; and guide means adjacent the rearward portion of said handle to coordinate with and provide tension to the guide pin.
On partially compressing the trigger the guide means provide tension on the guide pin and the ratchet engages the pawl. On completely compressing the trigger, the guide pin crosses over the top of the guide means causing the ratchet to be disengaged from the pawl.
In one embodiment the guide means described above are two cams attached to each side of the handle. In another embodiment, the stapling control means comprises two guide pins to coordinate with the two cams.
In yet another embodiment, the staple forming means described above is a track; a plurality of staples loaded and staple advancing means carried on the track; a track cover mounted on the track; an anvil surface mounted and a first bias means movably mounted on the cover, the said anvil surface terminating in a perpendicular flange; a staple adjacent the anvil surface; a retainer spring mounted on the anvil surface or a leaf spring on the terminal end of the track, and separating the staple from the flange; a guide block mounted on the cover adjacent the anvil surface; and a forming blade and a second bias means movably mounted on the guide means, the forming blade and the trigger having coordinating surfaces. The trigger has "overtravel". That is on compressing the trigger into the handle the staple forms on the flange before the guide pins cross over the top of the guide means causing the ratchet to be disengaged from the pawl.
In still another embodiment of the staple forming means described above, the track cover is adjacent the forward portion of the trigger. In still yet another embodiment of the staple forming means, the forming blade is between the forward portion of the cover and the anvil surface.
In yet another embodiment the stapling instrument described above comprises an indicator to indicate the number of staples remaining in the instrument. The indicator has an initial end visible in the handle. A terminal end is movably mounted on the staple advancing means such that on releasing the trigger, the first bias means pulls the terminal end and thus moves the initial end of the indicator.
A method of using the stapling instrument is within the scope of this invention.
A method of closing a wound or of connecting skin or fascia comprises: joining the adjacent edges of the wound or skin or fascia; placing the stapling instrument described above adjacent to the would or to the skin or fascia; compressing the trigger into the handle; and releasing the trigger and advancing the instrument, whereby a formed staple is placed between the edges.